If anyone happens to agree on th blitzkrieg thing I think it should be made so that it is a possible promotion after strength, (whatever that star thing is that adds 10% strength) and it gives +15% when attacking a city to give 25% in total with the star promotion. This way it would be possible to get an army equipped with the upgrade. I was thinking it could perhaps let you go through woodland and hills faster but historically it worked by charging down main lines of communication like the existing promotion (commando?) It should allow for multiple attacks per turn and faster road movement with the 15% city attack bonus. The road movement would be most important to cover much ground in a short time.